8 de fevereiro de 2015

Why violent crime is plummeting in the rich world

Efforts to explain a big drop in violent crime in many nations may help turn the tide in places where murder rates are stubbornly high

VIOLENT crime is on the retreat in most advanced economies. The latest US figures, for 2013, show that murder rates are lower now than in the early 1960s. In the same year, homicides in Japan hit a post-war low. In England and Wales the level of violence has dropped by 66 per cent since the latest peak in 1995.

In fact, big falls in homicides have happened in virtually all developed societies over the past 20 years. In the US, it is clear that the decline in violence extends to robbery, assault, rape, child maltreatment, domestic abuse and school bullying.

Why crime rose sharply in the second half of the 20th century before falling dramatically is open to debate. The causes are complex, and we are only starting to unravel them. It is also clear that in some nations homicide rates remain stubbornly high.

Against this backdrop, leading scholars believe that non-conflict violence could be halved across the world in the next 30 years.

So what have we learned from the recent crime fall in developed nations that could help? Some explanations are controversial – for example, linking it to the harmful impact of lead exposure, shown to heighten aggression and dysfunctional behaviour, and the banning of lead in petrol – but others are more broadly accepted.

A drop in societal violence often appears to be linked to social control technologies, including monitoring technologies, as well as increased control over disorderly conduct, and systems aimed at early identification of offenders. Some of the decline in crime across the Western world is probably a side effect of building more effective security and surveillance technologies into everyday life. These include central deadlocking systems in vehicles, better and more widespread home protection technologies, more CCTV cameras, and the move away from a cash-based economy. This raises important issues for reducing violence in developing nations, as it implies that violence prevention needs to be built in from the start, for example, in communication technologies and urban infrastructure.

In addition, any attempt to shift high violence rates must note that homicide declines are often triggered by influential groups or individuals emphasising the importance of self-control, civility and respect, changing societal views on harming others. Over the last 20 years much evidence suggests that in the West we have become less tolerant of violence, maybe as part of an ongoing civilising process that stretches back centuries. Bullying is no longer seen as a normal part of going to school, nor is it acceptable for parents to lash out at children, and tolerance of racially and sexually abusive language has shrunk. The public outcry about recent sexual abuse scandals in the UK involving high-profile individuals is not a sign that things are getting worse. Most of the offences date back decades anyway. What it does show is that we have become more intolerant of abusive behaviour by powerful people.

Improving policing in nations with stubbornly high violent crime is also important. This is another likely factor driving the current decline in violence in the West, where evidence-based policing methods started to take hold in the final decade of the 20th century. On this front, Lawrence Sherman, director of the Institute of Criminology at the University of Cambridge, recommends using the "triple-T" strategy: targeting scarce resources by focusing on predictable concentrations of crime and disorder; testing police practices to help choose those that work best to reduce harm; and tracking the delivery and effects of those practices.

Longer-term trends are also informative, especially in homicide – which has gone down in recent centuries in wealthier countries, despite intermittent upsurges. Historically, homicide rates have declined where states established an effective rule of law, curbing the corruption of officials, gaining control over private protection markets, and where states became more legitimate through accountable institutions, winning greater public trust. Any strategy to reduce violent crime in less-developed parts of the world must therefore also target political elites, who must commit to the rule of law, improved governance and inclusive state services.

Tackling violence in countries where it remains stubbornly high is important for economic as well as humanitarian reasons. The Copenhagen Consensus Center, which promotes an evidence-based approach to improving welfare worldwide, puts the global costs of violence, excluding conflicts, at $9.5 trillion a year, equivalent to around 11 per cent of world GDP. Homicides, violent crime, child abuse, domestic violence and sexual violence account for most of the cost.

While studies of downward crime trends offer guidance, if we are to turn global violence reduction into a coherent field of action, we need a lot more knowledge. We need monitoring systems that describe different kinds of violence at global, national and regional levels so we can direct action to where it is needed most. Additionally, we will need to overcome the massive gap between where the knowledge is and where the needs are greatest.

Half of all the world's 450,000 homicides each year occur in just 20 countries. All are in Latin America or sub-Saharan Africa, account for a mere 10 per cent of the world population, and have very limited research capacity. In contrast, 95 per cent of all knowledge on effective violence prevention relates to the US and wealthy European countries.

While work continues to fully understand the crime declines in these countries, it is now essential to build research capacity in low and middle income countries too, so they can follow suit and enjoy a safer future.

This article appeared in print under the headline "Holding violence down"

Manuel Eisner heads the Violence Research Centre at the University of Cambridge Institute of Criminology